[llvm] [Scalarizer] Ensure valid VectorSplits for each struct element in `visitExtractValueInst` (PR #128538)

[Farzon Lotfi via llvm-commits]

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@@ -1083,6 +1082,18 @@ bool ScalarizerVisitor::visitExtractValueInst(ExtractValueInst &EVI) {
   std::optional<VectorSplit> VS = getVectorSplit(VecType);
   if (!VS)
     return false;
+  for (unsigned I = 1; I < OpTy->getNumContainedTypes(); I++) {
+    std::optional<VectorSplit> CurrVS =
+        getVectorSplit(cast<FixedVectorType>(OpTy->getContainedType(I)));
+    // It is possible for VectorSplit.NumPacked >= NumElems. If that happens a
+    // VectorSplit is not returned and we will bailout of handling this call.
+    // The secondary bailout case is if NumPacked does not match. This can
+    // happen if ScalarizeMinBits is not set to the default. This means with
+    // certain ScalarizeMinBits intrinsics like frexp will only scalarize when
+    // the struct elements have the same bitness.
+    if (!CurrVS || CurrVS->NumPacked != VS->NumPacked)
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farzonl wrote:

So this works and I know its what I suggested in the ticket, but it seems like we are essentially just saying to Scalarize only if`ScalarizeMinBits` is 0.

I'm the person that added `if (!CurrVS || CurrVS->NumPacked != VS->NumPacked) return false;` to `splitCall` so essentially what I'm asking is if thats the right fix?

https://github.com/llvm/llvm-project/pull/128538